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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

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Diss Factsheets

Physical & Chemical properties

Dissociation constant

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Administrative data

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Reference
Endpoint:
dissociation constant
Type of information:
(Q)SAR
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
results derived from a valid (Q)SAR model and falling into its applicability domain, with adequate and reliable documentation / justification
Justification for type of information:
The substance is within the applicability domain of the selected (Q)SAR method.
Qualifier:
according to guideline
Guideline:
other: calculation
Version / remarks:
Software: pKalc version 3.2
Principles of method if other than guideline:
Since the water solubility of the test substance is very low, both the titration method and the spectrophotometric method are not applicable to determine the dissociation constant(s) of the test substance in, water. Therefore no dissociation constant(s) could be determined experimentally. As an alternative, the pKa values were calculated using the calculation method.
GLP compliance:
not specified
Specific details on test material used for the study:
CAS No.: 162492-07-1; Batch No.: lab; Purity: unknown by the sponsor, treated as 100 % pure; Appearance: white to off-white solid
Dissociating properties:
no
Remarks on result:
not determinable

Acidic groups: none. Basic groups: -4.2 (Carbamide); -3.7 (Carbamide); -3.2 (Carbamide); -0.2 (R-O-R); 0.3 (R-O-R); 0.8 (R-O-R). Based on these results, it was concluded that the test substance has no pKa values in the pH range 1-14.

Conclusions:
Under the study conditions, the following pKa values were calculated for the test substance: acidic groups: none, basic groups: -4.2 (carbamide); -3.7 (carbamide); -3.2 (carbamide); -0.2 (R-O-R); 0.3 (R-O-R); 0.8 (R-O-R). Based on these results, it was concluded that the test substance has no pKa values in the pH range 1-14.
Executive summary:

A study was conducted to determine the dissociation constant(s) of the test substance in water by calculation using pKalc version 3.2 software (module in PALLAS version 2.1). Under the study conditions, the following pKa values were calculated for the test substance: acidic groups: none, basic groups: -4.2 (carbamide); -3.7 (carbamide); -3.2 (carbamide); -0.2 (R-O-R); 0.3 (R-O-R); 0.8 (R-O-R). Based on these results, it was concluded that the test substance has no pKa values in the pH range 1-14 (Willems, 2002).

Description of key information

The dissociation constant(s) in water were determined by calculation using pKalc version 3.2 software (module in PALLAS version 2.1) (Willems, 2002).

Key value for chemical safety assessment

Additional information

The test substance has no pKa values in the pH range 1-14.